Complementary Diode Logic
Original Publication Date: 1986-Jun-01
Included in the Prior Art Database: 2005-Mar-09
This article describes the use of high capacitance diodes and a complementary NPN-PNP inverter to produce a high speed, low power logic circuit. High transient base current must be provided to the base of a bipolar transistor if a fast transition between logic states is to be achieved at its collector, but after the transition has completed, base current should be reduced to the minimum amount necessary to retain the new state. This is accomplished in the complementary diode logic (CDL) circuit by coupling the input transition into and out of the inverter bases through diodes having high shunt capacitance, and then retaining the logic state with high value resistors. The diodes also serve as logic gates. The CDL NAND and NOR circuits shown in Figs.